Field of the Invention
The present inventions relate to high power laser systems, high power laser tools, and methods of using these systems and tools for removing structures objects, and materials, and in particular, structures, objects, and materials in difficult to access locations and environments, such as offshore, underwater, or in hazardous environments, such as pipelines, nuclear and chemical facilities. Thus, the present inventions relate to high power laser systems, high power laser tools, and methods of using these systems and tools for removing structures, objects, and materials located offshore, on an offshore coastal shelf, on a continental shelf, in coastal waters, above the surface of a body of water, below the surface of a body of water, below and above the surface of a body of water, on the bottom of a body of water, e.g., the seafloor, below the bottom of a body of water, e.g., below the seafloor, and combinations and variations of these. In particular, the present inventions relate to the removal of offshore structures, such as: platforms used for the exploration and production of hydrocarbons; oil and gas wells; oil and gas fields; platforms used to support windmills; structures used to support bridges, causeways or piers; pipelines; and power cables.
As used herein, unless specified otherwise “offshore,” “offshore activities” and “offshore drilling activities” and similar such terms are used in their broadest sense and would include drilling and other activities on, or in, any body of water, whether fresh or salt water, whether manmade or naturally occurring, such as for example rivers, lakes, canals, inland seas, oceans, seas, bays and gulfs, such as the Gulf of Mexico. As used herein, unless specified otherwise the term “offshore drilling rig” is to be given its broadest possible meaning and would include fixed platforms, tenders, platforms, barges, dynamically positioned multiservice vessels, lift boats, jack-ups, floating platforms, drill ships, dynamically positioned drill ships, semi-submersibles and dynamically positioned semi-submersibles.
As used herein, unless specified otherwise the term “fixed platform,” would include any structure that has at least a portion of its weight supported by the seafloor. Fixed platforms would include structures such as: free-standing caissons, monopiles, well-protector jackets, pylons, braced caissons, piled-jackets, skirted piled-jackets, compliant towers, gravity structures, gravity based structures, skirted gravity structures, concrete gravity structures, concrete deep water structures and other combinations and variations of these. Fixed platforms extend from at or below the seafloor to and above the surface of the body of water, e.g., sea level. Deck structures are positioned above the surface of the body of water on top of vertical support members that extend down into the water to the seafloor and into the seabed. Fixed platforms may have a single vertical support, or multiple vertical supports, or vertical diagonal supports, e.g., pylons, legs, braced caissons, etc., such as a three, four, or more support members, which may be made from steel, such as large hollow tubular structures, concrete, such as concrete reinforced with metal such as rebar, and combinations and variations of these. These vertical support members are joined together by horizontal, diagonal and other support members. In a piled-jacket platform the jacket is a derrick like structure having hollow essentially vertical members near its bottom. Piles extend out from these hollow bottom members into the seabed to anchor the platform to the seabed.
The construction and configuration of fixed platforms can vary greatly depending upon several factors, including the intended use for the platform, load and weight requirements, seafloor conditions and geology, location and sea conditions, such as currents, storms, and wave heights. Various types of fixed platforms can be used over a great range of depths from a few feet to several thousands of feet. For example, they may be used in water depths that are very shallow, i.e., less than 50 feet, a few hundred feet, e.g., 100 to 300 feet, and a few thousand feet, e.g., up to about 3,000 feet or even greater depths may be obtained. These structures can be extremely complex and heavy, having a total assembled weight of more than 100,000 tons. They can extend many feet into the seafloor, as deep as 100 feet or more below the seafloor.
Examples of fixed platforms are provided in FIGS. 13 A-C. Where a triangular-pile-jacket, a rectangular-pile-jacket, and a gravity structure are illustrated, respectively. The conductors 2001 are shown within the structure of pile jacket platforms. To the extent utilized in the gravity structure, the conductors would be contained within the vertical support members 2002 of the gravity structure, and thus, are not shown in FIG. 13C. The conductors extend from the deck structures of the platform, 2005,a, b, c above the surface 2006 of the body of water 2007, to and into the seabed 2008. The conductors contain, e.g., hose, tubulars, which are used for among other things recovery of hydrocarbons from the formations below the seafloor. The size, weight, and variability of fixed platforms, associated conductors, and other structures and materials at, on, or within the seabed make their removal difficult.
As used herein, unless specified otherwise the terms “seafloor,” “seabed” and similar terms are to be given their broadest possible meaning and would include any surface of the earth, including for example the mud line, that lies under, or is at the bottom of, any body of water, whether fresh or salt water, whether manmade or naturally occurring.
As used herein, unless specified otherwise the terms “well” and “borehole” are to be given their broadest possible meaning and include any hole that is bored or otherwise made into the earth's surface, e.g., the seafloor or seabed, and would further include exploratory, production, abandoned, reentered, reworked, and injection wells.
As used herein, unless specified otherwise the term “drill pipe” is to be given its broadest possible meaning and includes all forms of pipe used for drilling activities; and refers to a single section or piece of pipe. As used herein, unless specified otherwise the terms “stand of drill pipe,” “drill pipe stand,” “stand of pipe,” “stand” and similar type terms are to be given their broadest possible meaning and include two, three or four sections of drill pipe that have been connected, e.g., joined together, typically by joints having threaded connections. As used herein, unless specified otherwise the terms “drill string,” “string,” “string of drill pipe,” string of pipe” and similar type terms are to be given their broadest definition and would include a stand or stands joined together for the purpose of being employed in a borehole. Thus, a drill string could include many stands and many hundreds of sections of drill pipe.
As used herein, unless specified otherwise the term “tubular” is to be given its broadest possible meaning and includes conductor, drill pipe, casing, riser, coiled tube, composite tube, vacuum insulated tube (“VIT”), production tubing, piles, jacket components, offshore platform components, production liners, pipeline, and any similar structures having at least one channel therein that are, or could be used, in the drilling, production, refining, hydrocarbon, hydroelectric, water processing, chemical and related industries. As used herein the term “joint” is to be given its broadest possible meaning and includes all types of devices, systems, methods, structures and components used to connect tubulars together, such as for example, threaded pipe joints and bolted flanges. For drill pipe joints, the joint section typically has a thicker wall than the rest of the drill pipe. As used herein the thickness of the wall of a tubular is the thickness of the material between the internal diameter of the tubular and the external diameter of the tubular.
As used herein, unless specified otherwise the term “pipeline” should be given its broadest possible meaning, and includes any structure that contains a channel having a length that is many orders of magnitude greater than its cross-sectional area and which is for, or capable of, transporting a material along at least a portion of the length of the channel. Pipelines may be many miles long and may be many hundreds of miles long or they may be shorter. Pipelines may be located below the earth, above the earth, under water, within a structure, or combinations of these and other locations. Pipelines may be made from metal, steel, plastics, ceramics, composite materials, or other materials and compositions know to the pipeline arts and may have external and internal coatings, known to the pipeline arts. In general, pipelines may have internal diameters that range from about 2 to about 60 inches although larger and smaller diameters may be utilized. In general natural gas pipelines may have internal diameters ranging from about 2 to 60 inches and oil pipelines have internal diameters ranging from about 4 to 48 inches. Pipelines may be used to transmit numerous types of materials, in the form of a liquid, gas, fluidized solid, slurry or combinations thereof. Thus, for example pipelines may carry hydrocarbons; chemicals; oil; petroleum products; gasoline; ethanol; biofuels; water; drinking water; irrigation water; cooling water; water for hydroelectric power generation; water, or other fluids for geothermal power generation; natural gas; paints; slurries, such as mineral slurries, coal slurries, pulp slurries; and ore slurries; gases, such as nitrogen and hydrogen; cosmetics; pharmaceuticals; and food products, such as beer.
Pipelines may be, in part, characterized as gathering pipelines, transportation pipelines and distribution pipelines, although these characterizations may be blurred and may not cover all potential types of pipelines. Gathering pipelines are a number of smaller interconnected pipelines that form a network of pipelines for bringing together a number of sources, such as for example bringing together hydrocarbons being produced from a number of wells. Transportation pipelines are what can be considered as a traditional pipeline for moving products over longer distances for example between two cities, two countries, and a production location and a shipping, storage or distribution location. The Alaskan oil pipeline is an example of a transportation pipeline. Distribution pipelines can be small pipelines that are made up of several interconnected pipelines and are used for the distribution to, for example, an end user, of the material that is being delivered by the pipeline, such as for example the feeder lines used to provide natural gas to individual homes. Pipelines would also include, for example, j-tubes that interconnect subsea pipelines with producing structures, pipeline end manifolds (PLEM), and similar sub-sea structures; and would also include flowlines connecting to, for example, wellheads. As used herein, the term pipeline includes all of these and other characterizations of pipelines that are known to or used in the pipeline arts.
As used herein, unless specified otherwise “high power laser energy” means a laser beam having at least about 1 kW (kilowatt) of power. As used herein, unless specified otherwise “great distances” means at least about 500 m (meter). As used herein the term “substantial loss of power,” “substantial power loss” and similar such phrases, mean a loss of power of more than about 3.0 dB/km (decibel/kilometer) for a selected wavelength. As used herein the term “substantial power transmission” means at least about 50% transmittance.
Discussion of Related Arts
Sub-Sea Drilling
Typically, and by way of general illustration, in drilling a subsea well an initial borehole is made into the seabed and then subsequent and smaller diameter boreholes are drilled to extend the overall depth of the borehole. Thus, as the overall borehole gets deeper its diameter becomes smaller; resulting in what can be envisioned as a telescoping assembly of holes with the largest diameter hole being at the top of the borehole closest to the surface of the earth. As the borehole is being extended, in this telescoping fashion, casing may be inserted into the borehole, and also may be cemented in place. Smaller and smaller diameter casing will be used as the depth of the borehole increases.
Thus, by way of example, the starting phases of a subsea drill process may be explained in general as follows. In the case of a floating rig, once the drilling rig is positioned on the surface of the water over the area where drilling is to take place, an initial borehole is made by drilling a 36″ hole in the earth to a depth of about 200-300 ft. below the seafloor. A 30″ casing is inserted into this initial borehole. This 30″ casing may also be called a conductor. The 30″ conductor may or may not be cemented into place. During this drilling operation a riser is generally not used and the cuttings from the borehole, e.g., the earth and other material removed from the borehole by the drilling activity are returned to the seafloor. Next, a 26″ diameter borehole is drilled within the 30″ casing, extending the depth of the borehole to about 1,000-1,500 ft. This drilling operation may also be conducted without using a riser. A 20″ casing is then inserted into the 30″ conductor and 26″ borehole. This 20″ casing is cemented into place. The 20″ casing has a wellhead, or casing head, secured to it. (In other operations an additional smaller diameter borehole may be drilled, and a smaller diameter casing inserted into that borehole with the wellhead being secured to that smaller diameter casing.) The wellhead, or casing head, would be located at the seafloor. A blowout preventer (“BOP”) is then secured to a riser and lowered by the riser to the sea floor; where the BOP is secured to the wellhead, or casing head. From this point forward, in general, all drilling activity in the borehole takes place through the riser and the BOP.
In the case of a fixed platform rig, once the drilling rig is positioned on the seafloor over the area where drilling is to take place, an initial borehole is made by drilling a 36″ hole in the earth to a depth of about 200-300 ft. below the seafloor. A 30″ casing is inserted into this initial borehole. This 30″ casing may also be called a conductor. The 30″ conductor may or may not be cemented into place. During this drilling operation a riser is generally not used and the cuttings from the borehole, e.g., the earth and other material removed from the borehole by the drilling activity, are returned to the seafloor. In the case of a fixed platform, the conductor extends from below the seafloor to above the surface of the water, and generally to the platform decking. Next, a 26″ diameter borehole is drilled within the 30″ casing, extending the depth of the borehole to about 1,000-1,500 ft. This drilling operation is conducted within the conductor. A 20″ casing is then inserted into the 30″ conductor and 26″ borehole. This 20″ casing is cemented into place and extends from below the seafloor to the above the surface of the sea. The 20″ casing has a wellhead, or casing head, secured to it. (In other operations, an additional smaller diameter borehole may be drilled, and a smaller diameter casing inserted into that borehole with the wellhead being secured to that smaller diameter casing.) With a fixed platform, the wellhead or casing head, is located above the surface of the body of water and generally in the decking area of the platform. A BOP is then secured to the wellhead or casing head. From this point forward, in general, all drilling activity in the borehole takes place through the BOP.
During completion of the well a production liner and within the production liner a production pipe are inserted into the borehole. These tubulars extend from deep within the borehole to a structure referred to as a Christmas tree, which is secured to the wellhead or casing head. (Other structures, in addition to, including, or encompassed by a Christmas tree, such as a tree, production tree, manifold and similar types of devices may be secured to or associated with the wellhead, casing head or conductor.) In sub-sea completions, the Christmas tree is located on the sea floor. In completions using a fixed platform, the Christmas tree is located above the surface of the body of water, in the platforms deck, atop the conductor. During production, hydrocarbons flow into and up the production pipe to the Christmas tree and from the Christmas tree flow to collection points where they are stored, processed, transferred and combinations of these. Depending upon the particular well, a conductor may have many concentric tubulars within it and may have multiple production pipes. These concentric tubulars may or may not be on the same axis. Further, these concentric tubulars may have the annulus between them filled with cement. A single platform may have many conductors and for example may have as many as 60 or more, which extend from the deck to and into the seafloor.
The forgoing illustrative examples have been greatly simplified. Many additional steps, procedures, tubulars and equipment (including additional equipment, power lines and pipelines on or below the seafloor) maybe utilized to proceed from the initial exploratory drilling of a well to the actual production of hydrocarbons from a field. At some point in time, a well or a collection of wells, will no longer be economically producing hydrocarbons. At which point in time the decision may be made to plug and abandon the well, several wells, and to additionally decommission the structures associated with such wells. As with the steps to drill for and produce hydrocarbons, the steps for plugging, abandoning and decommissioning are complex and varied.
Prior Methodologies to Remove Subsea Structures
There are generally several methodologies that have been used to remove structures from the seafloor. These methodologies may general be categorized as: complex saws, such as diamond saws: large mechanical cutters or shears; oxygen-arc or torch cutters; abrasive water jets; and explosives. Additionally, there may be other methodologies, including the use of divers and ROVs to physically scrap, chip, cut or otherwise remove material. All of these methodologies have health, safety, environmental, and reliability drawbacks.
A key and critical factor for any methodology that is used for the removal of subsea structures is that when subsea structures are cut-up for lifting out of the sea, these cuts must be complete. Thus, A. Culwell, Removal and Disposal of Deck and Jacket Structures, p. 52 (contained in “The Process of Decommissioning and Removing Offshore and Associated Onshore Oil and Gas Facilities”, 1997)(“A. Culwell”), notes that: “[i]t is crucial to the safety of the heavy lifts that these cuts be complete and reliable because they could not be examined for verification.” Culwell, at page 52, further notes that “abrasive water jet methodology . . . does not have guaranteed success and many cuts were repeated or completed with divers working inside the caisson legs after [abrasive water jet] cuts proved to be incomplete.”
Diamond saws and mechanical cutters have similar reliability failings. Diamond saws, as well as, abrasive water jets, are also slow in making their cuts, and thus, can be time consuming, which along with other factors, greatly adds to the overall removal costs. Oxygen-arc or torch cutters are similarly slow, may require divers, and thus, subject the divers to hazardous conditions, such as being inside of a caisson. Additionally, these cutters will not cut all types of material, for example concrete, which may require for example a diver to chip the concrete away.
Explosives, although reliable are dangerous to both humans and marine life, and in particular, to marine mammals. The use of explosives above the sea floor is being greatly restricted, and to protect marine life, these restrictions may extend to activities just below the sea floor, e.g., about 15 feet down or less. The abrasives used in abrasive water jets also have environmental concerns, although the study of this has only recently been started. The abrasive material used may prove dangerous to marine life and harmful to the environment.
High Power Laser Transmission
Prior to the recent breakthroughs of Foro Energy co-inventors it was believed that the transmission of high power laser energy over great distances without substantial loss of power was unobtainable. Their breakthroughs in the transmission of high power laser energy, in particular power levels greater than 5 kW, are set forth, in part, in the novel and innovative teachings contained in the following US Patent Application Publications Publication No. 2010/0044106; Publication No. 2010/0044104; Publication No. 2010/0044103; Publication No. 2010/0215326; and, Publication No. 2012/0020631, the entire disclosures of each of which is incorporated herein by reference.